iOS 4 ARC compatibility added.

As suggested by jerbeers, see https://github.com/jdg/MBProgressHUD/pull/37#commitcomment-862709.
Merge pull request #45 from matej/master

Added iOS 4 arc support.
Removed duplicate method declarations.
Merge pull request #46 from matej/master

Removed duplicated method declarations
Added support for iOS 4 ARC
New Retina resolution checkmark graphics
Merge branch 'master' into HEAD
Fixed crash bug that happened when using initWithView and then not adding the view to a superview
Merge branch 'master' of github.com:pereckerdal/MBProgressHUD
Merge pull request #52 from pereckerdal/master

Crash when initing MBProgressHUD object with initWithView and then not adding it to a superview
Add annular determinate mode, basically imitate Facebook.app image loading indicator
Merge pull request #55 from 5D/master

Add annular determinate, imitate Facebook image loading indicator
Merge pull request #50 from jazzgumpy/master

Retina resolution Checkmark graphics
Added the 2x checkmark image. #50
Add +findHUDForView:

This is useful if you want to immediately remove a HUD from some view, but
don't already have the HUDView retained somewhere. Find it using this method,
set the minShowTime to 0, then use hideHUDForView:animated: as usual.
Fix some typos

Conflicts:

	MBProgressHUD.h
Add method to hide and remove all the HUD subviews from a view

* The already present hideHUDForView:animated: method hide and
remove only one HUD found in the subviews (the last one).
There are cases when more than one HUD can be added to a view
(explicit add or just accidental fast user interactions):
the added hideAddHUDForView:animated: method hides and removes
all the HUD that have been previously added to a view.
Added allHUDsForView:, and refactored existing methods to use it.

- some additional cleanup and refactoring of class methods
Don't hide using animation if the HUD was never shown due to a grace time
Resetting showStarted when HUD gets hidden due to #20.